Why would someone want YOU to monitor their accounts?
You can install local monitoring to do the same. Why would I need 3rd party involved in MY monitoring of MY miners.
Not everyone is interested in installing HTTP servers, opening firewalls, forwarding router ports, upgrading / updating monitoring systems themselves. Some people just want simple, working systems.
yes you can install local monitoring but that will not tell you if your box is offline. If you box crashes how is it going to notify you that it is down. If the Pool crashes how is it going to notify you that it is down. I currently manage well over 5000 machines in our data center. All critical systems get monitored by a third party. Third party monitoring is not a replacement to local monitoring it is simply to ensure your systems are online. No single system is fool proof. Multiple monitors is a good thing.